Add ActiveRecord::Migration version to old migrations

Rails won't migrate from scratch without it.

db/migrate/20151112215012_create_projects.rb

@@ -1,4 +1,4 @@
-class CreateProjects < ActiveRecord::Migration
+class CreateProjects < ActiveRecord::Migration[4.2]
   def change
     create_table :projects do |t|
       t.timestamps null: false

db/migrate/20160120203924_add_slug_to_projects.rb

@@ -1,4 +1,4 @@
-class AddSlugToProjects < ActiveRecord::Migration
+class AddSlugToProjects < ActiveRecord::Migration[4.2]
   def change
     add_column :projects, :slug, :string
     add_index :projects, :slug, unique: true

db/migrate/20160513135058_create_songs.rb

@@ -1,4 +1,4 @@
-class CreateSongs < ActiveRecord::Migration
+class CreateSongs < ActiveRecord::Migration[4.2]
   def change
     create_table :songs do |t|
       t.timestamps null: false

db/migrate/20160719205342_add_position_to_projects.rb

@@ -1,4 +1,4 @@
-class AddPositionToProjects < ActiveRecord::Migration
+class AddPositionToProjects < ActiveRecord::Migration[4.2]
   def change
     add_column :projects, :position, :integer
   end

db/migrate/20160720004506_add_position_to_songs.rb

@@ -1,4 +1,4 @@
-class AddPositionToSongs < ActiveRecord::Migration
+class AddPositionToSongs < ActiveRecord::Migration[4.2]
   def change
     add_column :songs, :position, :integer
   end

db/migrate/20160720144917_create_users.rb

@@ -1,4 +1,4 @@
-class CreateUsers < ActiveRecord::Migration
+class CreateUsers < ActiveRecord::Migration[4.2]
   def change
     create_table :users do |t|
       t.timestamps null: false

db/migrate/20160722182558_add_ogg_to_songs.rb

@@ -1,4 +1,4 @@
-class AddOggToSongs < ActiveRecord::Migration
+class AddOggToSongs < ActiveRecord::Migration[4.2]
   def change
     add_attachment :songs, :ogg
   end

db/migrate/20160722195241_rename_audio_to_mp3.rb

@@ -1,4 +1,4 @@
-class RenameAudioToMp3 < ActiveRecord::Migration
+class RenameAudioToMp3 < ActiveRecord::Migration[4.2]
   def change
     rename_column :songs, :audio_file_name, :mp3_file_name
     rename_column :songs, :audio_content_type, :mp3_content_type

db/migrate/20160726012819_add_published_at_to_projects.rb

@@ -1,4 +1,4 @@
-class AddPublishedAtToProjects < ActiveRecord::Migration
+class AddPublishedAtToProjects < ActiveRecord::Migration[4.2]
   def change
     add_column :projects, :published_at, :datetime
   end

db/migrate/20160817014307_create_posts.rb

@@ -1,4 +1,4 @@
-class CreatePosts < ActiveRecord::Migration
+class CreatePosts < ActiveRecord::Migration[4.2]
   def change
     create_table :posts do |t|
       t.timestamps null: false

db/migrate/20160822180105_add_slug_to_posts.rb

@@ -1,4 +1,4 @@
-class AddSlugToPosts < ActiveRecord::Migration
+class AddSlugToPosts < ActiveRecord::Migration[4.2]
   def change
     add_column :posts, :slug, :string, unique: true, index: true
   end

db/migrate/20160824190847_add_tumblr_guid_to_posts.rb

@@ -1,4 +1,4 @@
-class AddTumblrGuidToPosts < ActiveRecord::Migration
+class AddTumblrGuidToPosts < ActiveRecord::Migration[4.2]
   def change
     add_column :posts, :tumblr_guid, :string
   end